The ab initio DFT energy calculations were carried out using the
Vienna ab initio simulation package (VASP).
[1]}, [2]}, [3]}
We employed the Perdew-Burke-Ernzerhof (PBE)[4]}
exchange correlation functional and Grimme’s D3 van der Waals
correction.[5]}
The core electrons were taken into account using the projector augmented wave
(PAW) method.
The valence electrons are expressed in terms of a linear combination of plane
wave basis functions with a cutoff at 400 eV.
Only the \(\Gamma \) -point of the Brillouin zone was computed.
